WO1996033824A1

WO1996033824A1 - Bending machine

Info

Publication number: WO1996033824A1
Application number: PCT/JP1996/001060
Authority: WO
Inventors: Toshiyuki Ooenoki; Toshiro Otani
Original assignee: Komatsu Ltd.
Priority date: 1995-04-27
Filing date: 1996-04-19
Publication date: 1996-10-31
Also published as: JPH08300048A; JP3431049B2; KR960037159A; KR100230167B1; US5899103A; TW305782B; DE19681349T1

Abstract

Bending angles of a plurality of bending points of a work are detected by means of an angle detecting unit while the work is being bent, and a bed driving means is controlled based on angle deviations between the detected angle values and target angles so as to impart a deformation to a bed supporting an upper mold or a lower mold, whereby a rough bending of the work is corrected.

Description

Specification

Bending machine technical field

The present invention relates to a bending machine, and more particularly to a bending machine that bends a plate-shaped work to a desired angle by relative movement between an upper mold and a lower mold. Background art

Conventionally, in a bending machine such as a breath brake, for example, a plate-like work is set between an upper mold and a lower mold, and the upper mold is lowered by a movable ram or the lower mold is moved. The desired bending is performed by raising the workpiece and pressing the workpiece between the upper and lower molds. By the way, when using a breath brake of this type to bend a particularly long work so that the bending line is along the longitudinal direction, as shown in FIG. 8, the central part of the bending line of the work is used. There was a problem that the so-called center-opening phenomenon occurs in which the bending of the incomplete was caused. The main cause of this center-opening phenomenon was

• The work has a variation in the use of material properties such as plate thickness along the longitudinal direction;

• The pressurization of both ends of the movable ram causes the machine itself to elastically deform due to the pressurization, resulting in uneven pressure distribution along the bending line of the work.

And the like.

In order to prevent such a center opening phenomenon, various center opening correction mechanisms have been conventionally proposed as follows.

(1) Japanese Patent Publication No. 49-14-1 4 753 The wedge-shaped key allows the upper and lower dies corresponding to the position where the bending angle becomes milder to approach the lower die in advance so that the pressing force during bending can be made uniform.

② Japanese Utility Model 6 — 5 4 4 16

At least three drive units for moving the ram up and down are provided, and a bending detection device for detecting the amount of bending of the ram is provided.The drive unit at the center is fed back based on the detection of the bending detection device. That are controlled in a controlled manner.

③ Tokuhei 3 — 5 3 0 4 6

Hydraulic cylinders for raising and lowering the mobile apron are provided near both sides of the mobile eblon, and hydraulic cylinders for correcting the deflection of the apron are provided at the fixed apron or almost at the center of the mobile eblon for raising and lowering. Pressure oil supplied to the hydraulic cylinder for deflection correction is controlled based on the pressure of the hydraulic cylinder and the length of the workpiece.

However, according to the chasing method disclosed in the above (1), it is not easy to inspect the bending angle along the longitudinal direction of the long workpiece, especially in the case of a long workpiece. Even if the amount of correction at each position is obtained, it is extremely rare that the correction is completed at once, and there is a problem that it is necessary to repeat the test bending inspection-adjustment several times. Further, such adjustment is required every time the bending length or the plate thickness is changed. Therefore, there is a problem that a long setup time is required and a large amount of work is required due to waste of adjustment work. Further, in the servo adjustment method disclosed in the above (1), since only the deflection of the ram is corrected, the upper and lower molds W that are actually involved in the bending of the workpiece are accurately exposed. There is a problem that it is not possible to cope with variations in the thickness of the work.

Furthermore, in the adjustment method disclosed in the above ③, the additional bending required Assuming that the relationship between the pressure and the deflection of the ebron (ram) is proportional, the pressure oil supplied to the hydraulic cylinder for correction is controlled by a control signal obtained by calculation. Also, there is a problem that it is not possible to perform the center-opening correction accurately responding to the variation of the plate thickness of (1).

The present invention has been made in view of the above problems, and has as its object to provide a bending machine capable of performing in-line high-precision bending without in-line opening without performing test bending. Is what you do. Disclosure of the invention

In order to achieve the above-mentioned object, a bending machine according to the present invention is a bending machine that bends a plate-like work to a desired angle by relative movement between an upper mold and a lower mold.

(a) angle detecting means provided on at least one side of the bending line of the workpiece and detecting bending angles at a plurality of points provided along the bending line of the workpiece;

(b) storage means for storing an angle deviation between the angle detection use at the plurality of points detected by the angle detection means and the target angle of the bending line of the mark during the bending of the mark,

(c) calculating means for converting the angle deviation recorded in the storage means into a position deviation of the upper die or the lower die relative to the target driving position of the current driving position,

(d) at least a bed driving means for driving the bead so as to deform the bead supporting the upper mold or the lower mold, and

(e) A control means WL for controlling the bead driving means so as to add a deformation amount corresponding to the positional deviation obtained by the arithmetic means to the above-mentioned bed. It is a special claim to have.

In the present invention, after the upper mold or the lower mold is driven to a predetermined driving position of the upper mold or the lower mold, the upper mold or the lower mold is provided along the bending line of the workpiece by the angle detecting means. Bending angles at a plurality of points are detected, and the angle deviation between the detected angle detection 值 and the target angle for bending the work is stored in the storage means. Next, the stored angle deviation is converted into a position deviation of the current driving position of the upper die or the lower die with respect to the target driving position, and the amount of deformation corresponding to the position deviation obtained in this manner is reduced. In addition, the control means controls the bed driving means so as to apply the upper mold or the lower mold to the bed supporting the upper mold or the lower mold. In this way, by detecting the bending angle in-line, the center opening amount is automatically corrected. Therefore, without trial bending, the entire length of the bending line of the work can be obtained even if the thickness of the work varies. Therefore, it is possible to improve the bending angle sugar content.

In the present invention, the control means, when continuously performing bending under the same processing conditions, adjusts the amount of deformation of the bead in the first bending corresponding to the previously input and stored processing conditions. It is preferable to control the bed driving means based on the above. This makes it possible to perform high-accuracy center-open correction while shortening the machining cycle time.

A plurality of the angle detecting means may be provided on both sides of the bending line of the work along the bending line. The angle detecting means may be movable in a direction parallel to a bending line of the work. By simultaneously detecting the bending angle of the work on the rainy side of the bending line of the work, the angular deviation can be accurately obtained even when the mold is misaligned. In addition, by making the angle detecting means movable, a single angle detecting means can bend the workpiece. It is possible to detect the bending angles at a plurality of points along the bending line on one side of the line.

The bed drive means includes:

(1) A wedge mechanism for driving the bead by sliding a plurality of wedges provided on the support portion of the upper mold or the lower mold,

(2) A linear actuator installed on the ram to which the above-mentioned bed is attached

③ At least three hydraulic cylinders for raising and lowering the ram to which the above-mentioned bed is attached,

ボール At least three ball screwdrivers that move up and down the ram to which the bed is attached

Etc. can be adopted.

Other objects of the present invention will be apparent from the detailed sharpness described below, however, the detailed sharpness and specific examples describe the most preferred embodiments, but are within the spirit and scope of the present invention. Various modifications and variations of the present invention will be apparent to those skilled in the art from the detailed description, and thus are described as specific examples. Simple sharps of the drawing

FIGS. 1 to 6 are drawings for sharpening a specific embodiment in which the folding and concealment according to the present invention is applied to a press brake.

Figure 1 is a front view,

Figure 2 is a plan view,

Figure 3 is a side sectional view,

Figure 4 shows the flowchart of the center opening correction control.

FIG. 5 is a graph showing the relationship of the bending angle to the bottom dead center position of the ram, and FIG. 6 is an explanatory diagram schematically showing a specific example of the center opening correction.

FIG. 7 is a side view according to another embodiment of the present invention. Figure 8 is a sharp view showing the work opening phenomenon. BEST MODE FOR CARRYING OUT THE INVENTION

Next, specific examples of the bending machine according to the present invention will be described with reference to the drawings.

A front view, a plan view and a side sectional view of a breath brake according to one embodiment of the present invention are shown in FIGS. 1, 2 and 3, respectively. In the breath brake of the present embodiment, a fixed table 2 is disposed in the longitudinal direction of the body frame 1 on the front of the body frame 1, and the ram 3 can move up and down in opposition to the fixed table 2. It has been A lower die (die) 5 is placed on the fixed table 2 through a lower pad 4, and an upper die (punch) 7 is placed on the lower end of the ram 3 through an upper pad 6. Is attached.

The ram 3 has a ¾-tooth shape in which an upper portion is provided with a turning portion and a convex portion alternately, and pole nuts 8 are attached to a plurality of (eight in this embodiment) concave portions, respectively. The ball nut 10 is fitted with a ball screw 10 rotatably supported on the body frame 1 via a bearing holder 9. Each ball screw 10 has a large-diameter driven burley 11 attached thereto, between each driven pulley 11 and each drive pulley 13 attached to the motor shaft of each servomotor 12. The timing belt 14 is suspended.

In this way, by rotating each servomotor 12 synchronously by the pressure operation of the foot switch 15, each ball screw 10 is synchronously rotated, and this causes the ram 3 to move up and down horizontally. . The moving amount of the ram 3 is detected by a linear encoder 16 disposed on the back side of the ram 3. In this embodiment, eight ball screws 10 are provided. However, this ball screw 10 has a small portion between the center and both ends of the ram 3. By providing at least three points, it is possible to correct the center opening of the work.

On the front and rear surfaces of the fixed table 2, three angle detection units 17 are provided, three each. Of these, the central angle detection unit 17 is fixed to the fixed table 2, and the left and right angle detection units 17 are mounted on the motor along the guide rails 18 that are mounted horizontally to the fixed table 2. It can be moved left and right by the drive of 19. In this way, the left and right angle detection units 17 are attached to the guide rails 18? By moving &, the bending angle at any three or more points along the bending line on both sides of the bending line of the work can be detected. Here, as described in, for example, Japanese Patent Application Laid-Open No. HEI 4-145315, the angle detection unit 17 is arranged so that a slit light or a series is formed on the outer surface of a bent bend. A light projecting means for projecting a large number of spot lights, an image means for imaging a linear projected image on a workpiece projected by the light emitting means, and an image projected by the image sensing means An arithmetic processing means for calculating the bending angle of the workpiece by performing the processing can be used. As the angle detecting unit, in addition to the optical type as in this embodiment, any other non-contact type such as a capacitance type, a differential transformer type, a magnetic type, or a contact type may be used. May be used.

Behind the fixed table 2, a pair of back stops 20 for abutting the rear end surface of the work is provided so as to be able to conceal the front and rear and adjust the left and right positions. Reference numeral 21 in FIGS. 1 and 2 denotes an operation panel that can be moved left and right with respect to the body frame 1 and can be slid forward and backward.

The mid-opening compensation of the work using the press brake constructed in this way is performed by eight servos for generating the main pressing force for this work. The driving is performed by independently controlling the driving of the motor 12, in other words, the eight ball screws 10. That is, each ball screw 10 is driven synchronously to a predetermined position, and at that position, the bending angle is detected by the angle detection unit 17, and the detected bending angle and the target angle of bending of the beak are determined. A correction drive amount for each ball screw 10 is calculated based on the angle deviation, and each of the ball screws 10 is driven by this correction drive amount.

Next, the center opening correction control will be described more specifically with reference to a flowchart shown in FIG.

S 1 to S 3: Enter the following various bending conditions when starting bending.

①Material, thickness, tensile strength

②Target bending angle

③ Shape data (bending length, pre-processed shape)

④Die data (punch shape, die shape)

角度 Angle crossing required (person δ)

The memory of the NC unit previously stores data on the bottom dead center position d of the ram 3 and the bending angle 0 and the springback angle for each bending condition (material, plate thickness, mold condition, etc.). ing. An example of this data is shown in Figure 5. In Fig. 5 (a), the solid line is a bending angle-lower dead center diagram when the work is pressed by both dies (hereinafter referred to as the pressurized state), and the chain line indicates that the load on the work is removed. (Hereinafter referred to as unloading.) FIG. The hatched area surrounded by the solid line and the chain line is the data on the springback angle (springback data). Fig. 5 (b) is an enlarged view of part A of the bending angle-bottom dead center diagram in the pressurized state in Fig. 5 (a). As shown in Fig. 5 (b), bending angle-bottom dead center The diagram can be approximated by a straight line when a narrow area is taken out. Next, in the NC device, based on the input conditions and the stored data, the target in the pressurized state that allows for the swingback angle The angle 0 is calculated, and the target bottom dead center d at which the target angle is 0 is automatically calculated. At this time, it is well known that if the input material properties 值 (Young's modulus, yield point, etc.) and the sheet thickness, etc., vary within the range of the standard, the angle after bending also varies. . Therefore, the above-mentioned item (1), bottom dead center d, is usually set to a plant that does not cause excessive bending in consideration of such variations.

S4 to S5: The NC device determines the position for performing angle detection from the input work shape data, and moves each angle detection unit 17 in a predetermined position by driving the motor 19. When the machining process is useful for an NC table or the like, the above-described steps S1 to S5 are automatically performed according to the stored data.

S6 to S7: When a machining start command is issued by the road pressure operation of the foot switch 15, the ram 3 is lowered by each pole screw 10 so that the ram 3 reaches the bottom dead center d. Stop at this bottom dead center.

S8 to S11: Bend angle of work is detected at each predetermined position by angle detection command. Next, when the difference between these detection angles is not within the intersection range, the correction amount of each ball screw 10 is adjusted so that the bending angle at each detection position becomes the smallest (severest) angle. The ball screw 10 is driven by the calculated correction amount. Thereafter, the bending angles at the respective predetermined positions are detected again, and the above operation is repeated until these bending angles fall within the intersection range.

Here, as schematically shown in FIG. 6, for example, in a breath brake in which the distance between the ram driving devices 22, 23, and 24 is 800 mm, and _t to consider the case of bending the work W to 9 0 -

Θ O 9 / P96 / 01060 In this case, the springback angle is calculated as 3 'and the target angle in the pressurized state is set to 87', and the target bottom dead center corresponding to this target angle is calculated as d. Suppose. However, since this bottom dead center is calculated as a value that does not allow bending to the target angle as described above, at this point it is usually a value shallower than the target angle 87 ·. If the variation in bending angle caused by factors such as deformation of the machine is conceptually represented as shown in the lower graph of Fig. 6, the bending angle at all angle detection positions is the largest. The drive amount of each ram drive unit 22, 23, 24 is calculated so as to reach the tight part (in this example, 88 at the point P). That is, the ram drive device 2 2 (left end) is 2 'shallower than the current condition, the ram drive device 23 (center portion) is 2' tighter than the present condition, and the ram drive device 24 (right end) is the present condition. May be controlled so as to be maintained. Based on these data and the data shown in FIG. 5 (b), the driving amounts of the ram drive units 22, 23 and 24 are +0.04 mm (up) and one 0.04 mm (down), respectively. , 0 mm (hold).

S12 to S17: When the difference between the detected angles falls within the intersection range, the variation in bending angle disappears along the entire length of the bending line of the workpiece W caused by factors such as deformation of the machine. Then, the average value 0 ′ of each of these detected angles is compared with the target angle P in the pressurized state.When θ ′ holds, the unachieved bending angle 0 ′-Θ Calculate the corresponding bottom dead center deviation δ ', and push each ball screw 10 equally by ff'. In the example shown in FIG. 6, since the peak W is still slightly bent (88 ′) with respect to the target angle 87 * in the pressurized state, each ram drive device 22, 23 and 24 are further lowered by 0.02 mm, which is equivalent to 1 · which is not reached by the angle. It should be noted that simply driving each of the ram drive devices 22, 23, 24 by the same amount in this manner generally requires only a very small amount of bending in bending. Except for the initial period, the bending load does not change significantly, and this is based on the reason that this bending load is not affected by the deformation of the machine, etc. in the minute range as described above. When each ball screw 10 is pressed evenly in this way, it is determined that the bent product is good, and the ram 3 is raised to complete the processing.

— When Θ,,, judge that the bent product is defective, notify the system if necessary, raise ram 3 and end the processing.

In the present embodiment, the bending angle detection by the angle detection unit 17 is performed in a state where a pressing force is applied to the work, but the work can be supported even when the driving die is separated from the work. If possible, the bending angle may be detected in the unloading state, and the ram 3 may be driven based on the angle deviation between the detected bending angle and the target angle. This has the advantage that the driving force required to drive the ram 3 can be reduced.

By the middle-opening correction control of the present embodiment, it is possible to obtain a bent product that fits within the desired angle range along the entire length of the bending line of the workpiece without performing a complicated process such as trial bending. As a result, it is possible to accurately perform bending of a long object, which is generally difficult.

In the present embodiment, the variation of the springback angle is not considered, but for the material whose springback angle varies widely, the material is once unloaded in the final step, and this unloading is performed. It is also possible to perform re-correction based on the swingback angle obtained from the bending angle measured later.

By the way, since the correction amount as shown in the above-mentioned flow chart is calculated for each bending process, it is time-consuming. If the bending process is performed continuously, the ball screw drive should be controlled based on the amount of correction in the first bending process corresponding to the previously input and stored processing conditions. Is preferred. This makes it possible to perform high-precision, middle-open control while shortening the machining cycle time.

In the present embodiment, the position of the ram is controlled by the ball screw, but at least three hydraulic cylinders that generate a main pressing force are used instead of the driving means by the ball screw. It is also possible to control the ram position by controlling the cylinder.

In this embodiment, the center opening correction is performed by directly controlling the position of the ram.However, an embodiment using a secondary driving means such as a hydraulic pressure as a means for deforming the ram is also possible. It is. In this case, it is preferable to calibrate the hydraulic pressure and the ram deformation amount as the mechanical characteristic data in advance, store the data in the storage unit, and perform pressure control or the like based on the data.

Further, as shown in FIG. 7, an embodiment using a wedge mechanism provided on a support portion of a lower mold (or an upper mold) is also possible. In the embodiment shown in FIG. 7, a plurality of thrust support members 25 each having a lower surface formed as an inclined surface 25 a are provided between the fixed table 2 and the lower bed 4. A plurality of wedge-shaped keys 26 are provided between the thrust support member 25 and the upper surface of the fixed table 2. Each wedge-shaped key 26 is slid in the left and right direction in the figure via a castle speed mechanism 28 by a drive source 27 composed of a servo motor or a stepping motor or the like. Therefore, the upper and lower positions of the die 5 are controlled by independently controlling the driving of the respective driving sources 27 corresponding to the respective wedge keys 26. In this embodiment, three angle detection units 17 are provided on both sides of the bending line of the workpiece, respectively, but the angle detection units 17 are provided on both sides of the bending line of the workpiece. One angle detection unit 17 may be provided to detect the bending angles at a plurality of points by running each angle detection unit 17 along the entire length of the bending line of the work. Of course it is good. Alternatively, it may be provided on only one side of the bending line of the work, and only the bending angle on one side may be detected to estimate the total bending angle.

In the present embodiment, an example in which the lower mold is fixed and the upper mold is driven and applied to a so-called single-bar drive type breath brake has been described. It is needless to say that the present invention can be applied to a so-called under-drive breath brake for driving a mold, and further to a breath brake for driving both dies.

As described above, the present invention is clear _t Such modifications can be varied in many ways without departing from the spirit and scope of the invention, and all such modifications bright K to those skilled in the art, Changes are within the scope of the »claim.

Claims

Range of 2t

. Bending to bend the plate-like peak to a desired angle by relative movement between the upper mold and the lower mold:

(a) angle detecting means provided at least at one side of the bending line of the work and detecting bending angles at a plurality of points provided along the bending line of the work;

(b) recording means for storing an angle deviation between the angle detection plant at the plurality of points detected by the angle detection means and the target angle of bending the work during the bending of the work,

(c) calculating means for converting the angle deviation recorded in the recording means into a positional deviation of the current driving position of the upper die or the lower die from the target driving position,

(d) at least a bead driving means for driving the bead for supporting the upper die or the lower die so as to impart deformation to the bead.

(e) control means for controlling the bead drive means so as to apply to the bead an amount of deformation corresponding to the position deviation obtained by the arithmetic means

A bending machine that specializes in having

The control means, when performing bending processing under the same processing conditions continuously, based on the deformation amount of the bed in the first bending processing corresponding to the processing conditions inputted and recorded in advance. Ft. The bending machine according to claim 1, wherein the bend drive unit is controlled. The angle detection unit includes a plurality of the angle detection units on the rainy side of the bending line of the work along the bending line. 3. The bending machine according to item 1 or 2, wherein the bending machine is provided one by one.

The angle detecting means is a direction parallel to a bending line of the work. 4. The bending machine according to claim 1, wherein the bending machine is movable.

The bead driving means is a wedge mechanism that drives the bead by sliding a plurality of wedges provided on a support portion of the upper mold or the lower mold. The bending machine according to any one of claims 1 to 4, which is to be considered extreme.

The bending machine according to any one of claims 1 to 4, wherein the bead driving means is a linear actuator provided on a ram to which the bead is attached.

The claim according to any one of claims 1 to 4, wherein the bead driving means is at least three hydraulic cylinders for raising and lowering a ram to be attached to the bead. Bending machine.

The above-mentioned bead driving means is characterized in that it is a ball screw driven by at least three motors for raising and lowering a ram to which the above-mentioned bead is attached, which is characterized by Si [ The bending machine described in any of the above.